Propeller blade ice preventer



Aug. 1, 1944. E. MARTIN PROPELLER BLADE ICE PREVENTER Original Filed Dec. 15, 1959 INVENTOR EIIEMJZII'H 9M ATTORNEY Patented Aug. 1, 1944 PROPELLER BLADE ICE PREVENTER Erle Martin, West Hartford, Conn., assignor to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Original application December 13, 1939, Serial No. 308,995. Divided and this application October 24, 1940, Serial No. 362,601

8 Claims.

This. invention relates to improvements in aeronautical propeller blades and this application is a division of United States application Serial No. 308,995,-filed December 13, 1939, by Erle Martin for Laminated propeller blades.

An object of the invention resides in the provision of an improved propeller blade-having conduits for de-icing fluid built into the propeller blade structure.

Other objects and advantages will be more particularly pointed out hereinafter or will become apparent as the description proceeds.

In the accompanying drawing, in which like reference numerals are used to designate similar parts throughout, there are illustrated for the purpose of disclosing the invention, several details of construction of the improved propeller blade including three slightly variant forms of built-in de-icing fluid conduits. The drawing, however, is for the purpose of illustration only and is not to be taken as limiting the invention as it will be apparent to those skilled in the art that various changes in the illustrated method and construction may be resorted to without in any way exceeding the scope of the invention.

In the drawing, Fig. 1 .is an elevational view of the central portion of an aeronautical propeller showing the application of conduits for propeller de-icing fluid applied thereto, a portion of one of the blades being shown in section to illustrate the application thereto of one form of built-in de-icing fluid conduits.

Fig. 2 is a sectional view on the line 22 of Fig. 1.

Fig. 3 is a partly sectional view of a propeller blade showing the application of a somewhat modified form of de-icing fluid conduit thereto.

Fig. 4 is a partly sectional view of a propeller blade showing the application thereto of a still further modified form of de-icing fluid conduits,

and Fig. 5 is a sectional view on the line 55 of Fig. 4 looking in the direction of the arrows.

Referring to the drawing in detail, the exterior surface of the propeller blade I6 is formed in any suitable manner and in the designs shown on the blade surface adjacent its hub end is formed by a fairing 40 made of any suitable material such as expanded rubber or balsa wood permanently secured to the blade core. The leading edge of this fairing may be reinforced, if desired, by a cover member 42. of any suitable material such as 1 metal. This fairing supports a de-icing device which will now be described.

A tube or conduit 44 leads from a suitable source. of supply of de-icing fluid, not illustrated,

through a fixed shield 46 to a collector ring .48

space for retaining fluid and distributing it about.

the circumference of the ring. A tube 54 leads from the ring adjacent to the location. of each propeller blade and projects into the bottom end of the portion of the blade formed by the fairing 40 as indicated at 56. This tube may be supported on the hub by suitable means such as the clamp 58. Within the bottom end of the portion of the blade formed by the fairing there is provided a curved receptacle 60 having a curvature centered on'the axis of rotation of the blade and extending for substantially the entire width of the blade, as is particularly illustrated in Fig. 2. A conduit 62 leads from this receptacle 60 outwardly through portions of the blade formed by the fairing 40 to a location adjacent the termination of the fairing portion of the blade, as indicated at 64. Intermediate its length the conduit 62 is provided with a plurality of circumferential reductions as indicated at 66, 68, 10 and 72 and from each of these reductions a conduit, as indicated respectively at 14, I6, 18 and 80, leads to the exterior of the leading edge cover 42; through suitable apertures in the cover to bring proportionate quantities of de-icing fluid to the exterior of the propeller blade along the leading edge thereof. As the blade rotates centrifugal force moves this fluid out along the blade towards the tip end and the air forces tend to spread the fluid from the leading edge backwardly towards the trailing edge thus providing a coating of deicing fluid over the entire forward inner portion of the propeller blade where ice is likely to form.

By placing the conduit 62 within the interior of the blade, such as in the fairing portion 40 a greatly improved propeller construction is obtained in which there is no break necessitated in the streamlined contour of the exterior surface of the propeller and in which-the conduit is firmly supported and may be extended to carry the fluid a greater distance out along the length of the propeller blade.

In the form shown in Fig. 3 a plurality of tubes, as indicated at 82, 84 and 86, extend from the receptacle outwardly through the blade por tion formed by the fairing 40 and terminate at apertures spaced along the length of the blade.

leading edge cover 42 In this case the tube 12, first terminating, is made larger than the other tubes to carry a greater quantity of fluid to the larger shark end portion of the blade.

In the form shown in Figs. 4 and 5 the receptacle 60 is dispensed with and the tube 54 is provided with-a loop surrounding the shank end of the blade to render the tube'sufliciently flexible to follow the pitch changing movements of the blade. The outer end of this tube is then rigidly secured, as indicated at 88, to the end of a conduit 90 extending outwardly through the portion of the blade formed by the shank fairing 40 which conduit may be provided with taps leading to the exterior of the blade at spaced intervals along its length,'as is clearly illustrated in Fig. 1.

While various details of construction of the improved blade have been hereinabove described and illustrated in the accompanying drawing it is to be understood that the invention is not limited to the details of construction 50 illustrated and described, but that various changes in the mechanical construction of the improved blade may be resorted to as come within the scope of the sub-joined claims.

Having now described the invention so that others skilled in the art may clearly understand the same, what it is desired to secure by Letters Patent is as, follows:

1. In combination, a propeller blade having a relatively fiat outer portion and a shank portion, a shank fairing forming part of the shank portion of the blade and formedof material lighter than the material of the remainder of said blade firmly secured to the other part of the shank portion of said blade, and de-icing fluid conduits extending through and. carried by said shank fairing and leading to spaced openings in the surface of said blade.

2. In combination, a propeller blade having a flat outer portion and a shank portion, a shank.

fairing forming part of the shank portion of the blade and formed of material lighter than the material of the remainder of said blade firmly secured to the other part of the shank portion of said blade and extending outwardly beyond said shank portion, a leading edge cover for said shank portion, and de-icing fluid conduits extending through said shank fairing and leading to spaced apertures in'said cover.

3. In combination, a propeller blade having a flat outer portion and a shank portion, a shank fairing forming part of the shank portion of the blade and formed of material lighter than the material of the remainder of said blade firmly secured to the other part of the shank portion of said blade, a curved receptacle in the end of said shank fairing for receiving de-icing fluid, and

conduits leading from said receptacle to the exterior of the leading edge of said blade at spaced intervals along the length of said leading edge.

4. In combination, a propeller blade having a relatively fiat outer portion and a shank portion, a shank fairing forming part of the shank portion of the blade and formed of material lighter than the material of the remainder of said blade firmly secured to the other part of the shank portion of said blade and extending outwardly beyond said shank portion, a curved receptacle in the end of said shank fairing for receiving de-icing fluid, and conduits leading from said receptacle to the exterior of the leading edgeof said shank fairing at spaced intervals along the length of said fairing, the conduit leading to the exterior of said fairing at the hub end thereof having a greater capacity than the other of said conduits.

5. In combination, a propeller blade and a shank portion, said. shank portion including a fairing secured thereto and de-icing fluid conduit means in and carried by said shank fairing and leading to spaced openings in the surface of said fairing for transmitting de-icing fluid to the surface of said fairing.

6. In a controllable pitch aeronautical propeller having fairing members secured to the blades close to the propeller hub, means to feed de-icing fluid to the propeller hub, andconduit means leading therefrom to the leading edges of respective fairings.

'7. In a controllable pitch aeronautical propeller having fairing members secured to the blades close to the propeller hub, means to feed de-icing fluid to'the propeller hub, and conduit means leading therefrom to the leading edges of respective fairings, said conduit means termidating in outlets adjacent the outer ends of the fairings for spreading de-icing fluid along the leading edges of the propeller blades.

8. In combination, a propeller blade and a shank portion, said shank portion including a fairing secured thereto and de-icing fluid conduit means in and carried by said shank fairing and leading to an opening in the surface of said fairing for transmitting de-iclng fluid to the surface of said fairing.

- ERLE MARTIN. 

